Conventional household toilets have a flush-water holding tank typically mounted above the toilet bowl. The holding tank is filled to a preset level with water so that, when the toilet is flushed, a substantial quantity of water is available to provide a thorough flushing action. Marine toilets typically installed in pleasure craft have no tank. Instead, a flushing pump is used to propel flushing water though a water supply conduit which extends from an intake opening in the boat's hull. In this way, seawater rather than fresh water can be used to flush the toilet, reducing the size and weight of the toilet and avoiding unnecessary consumption of the on-board supply of fresh water.
Although the conventional "tankless" marine toilet performs its basic functions satisfactorily, it has significant shortcomings. Standing water in the toilet system often creates odors which are particularly unpleasant in the small and poorly ventilated confines of the craft's cabin space. The use of seawater for flushing, rather than fresh water, aggravates the problem because seawater typically contains salt, microorganisms, plant life, and other contaminants which often intensify the odors.
U.S. Pat. No. 5,142,707 issued to Frederick C. Prue on Sep. 2, 1992, the disclosure of which is incorporated herein by reference, describes an highly effective additive injector that can be used to deodorize, lubricate and clean a tankless marine toilet system. That arrangement as described in the Prue patent is typically connected in the flush water intake as indicated generally at 11 in FIG. 1 of the drawings. The injection unit 11 is serially connected with a flush water conduit 13 which carries flushing water from a through-the-hull intake port 15 to a toilet bowl 19. A gate valve 20 connects the conduit 13 to the intake port 15. When closed, the valve 20 prevents sea water from entering the toilet system via the intake port 15.
Waste from the toilet bowl 19 flows through a drain conduit 21 and then passes either through a gate valve 23 to a through-the-hull outlet port 25, or alternatively through a gate valve 27 to a collection tank 31. When the waste is to be expelled through the outlet port 25, the gate valve 23 is open and the valve 27 is closed. When the waste is to be placed in the collection tank 31, valve 23 is closed and valve 27 is opened. Collection tank 31 is provided with a vent 33 and a waste removal conduit 35 which extends to a deck plate 37 which provides access to the collection tank for waste removal. In order to provide an adequate flow of flushing water, a hand-operated flushing pump of the type illustrated at 35 in FIG. 1 may be serially connected with the flush water conduit 13 adjacent the toilet bowl 19. Other pumping mechanisms may be employed, both in the flush water intake and in the outlet drainage conduits, to provide the desired flows.
While the additive injection unit as described in U.S. Pat. No. 5,142,707 and shown in FIG. 1 has proven to be highly effective, it is often difficult to securely install. The marine toilet and the input water line into which the additive injector must be installed are typically placed in a cramped environment, and adjoining bulkhead or cabin walls can be oriented in many different ways, making it difficult to properly secure the injector while positioning it in an orientation which best promotes proper functioning and access.
It is accordingly a general object of the present invention to provide an improved additive injection unit which is easy to install and use for sanitizing, deodorizing, lubricating and/or winterizing a marine toilet system.
It is a further object of the present invention to provide an additive injection unit which may be readily mounted in the a desired position by securing it to an existing structure which may have any one of a wide variety of orientations.
It is a further object to provide an improved marine toilet additive injection unit including integral adjustable mounting means for securing the unit in the proper position within an existing marine toilet system.